Shaft attachment for dental motors.



PATENTED APR. 18, 1905.

W. B. 6; E. P. ALFORD.

SHAFT ATTACHMENT FOR DENTAL MOTORS.

APPLICATION FILED JUNE 17,1904.

M w m UNITED STATES Patented April 18, 1905.

PATENT OFFICE.

VILLIAM BARKIN ALFORD AND EDTVIN P. ALFORD, OF SUMTER, SOUTH CAROLINA.

SHAFT ATTACHMENT FOR DENTAL MOTORS.

SPECIFICATION forming part of Letters Patent No. 787,350, dated April18, 1905.

Application filed June 1'7, 1904. Serial No. 213,021.

To (tZl whom it may concern.-

Be it known that we, WILLIAM BARKIN AL- FORD and EDWIN P. ALFORD,citizens of the United States, residing at Sumter, in the county ofSumter and State of South Carolina, have invented new and usefulImprovements in Shaft Attachments for Dental Mo tors. of which thefollowing is a specification.

This invention is an improved shaft connection particularly suitable forthe attachment of the flexible shaft of a dental handpiece to thedriving-shaft of a motor. the object being toafford means whereby thetool may be started or stopped at will without stopping the motor. Theconnection includes a slip-joint, in one position of which the shaftsare coupled and in the other position of which they are uncoupled.

Improved details will also appear with respect to the means forsupporting the motor and the handpiece-shafts and for driving a rotarybrush.

in the accompanying drawings, Figure 1 is a front elevation of theapparatus. Fig. 2 is a side elevation. Fig. 3 is a top plan view. Fig. 4is a detail of the shaft connection.

Referring specifically to the drawings. 6 indicates the motor-casing,and 7 the shaft of the motor. The. latter is carried in bearings in arms8, projecting from a standard 9, the motor being located between thearms. On the outside of one of the arms, extending around theshaft-bearing, is a nipple 10, which is threaded on the inside andoutside. The inside threads receive the threaded end of a tube 11 andthe outside threads receive the threaded end of a coupling-sleeve 13.

12 indicates a sleeve or tubular piece which is carried on the end ofthe flexible-shaft covering, which is indicated at 12. This sleeve 12 isenlarged to proper size to have an easy fit over the tube 11, on whichit is slidable lengthwise to connect or disconnect the shaft. Theoutward movement is limited and the parts retained in place by flanges14: and 15. projecting inwardly and outwardly, respectively, from thecoupling-sleeve 13 and the piece 12.

The rigid end piece of the flexible shaft is indicated at 16 and the endthereof fits with- 5 in an axial bore 17 in the end of the motorshaft 7.The end piece 16 carries thereon an adjustable collar 18, which has apin 19, adapted to enter a notch 20 in the end of the shaft 7 to couplethe shafts together.

As stated before, the piece 12 and the shaftcovering and flexible shaftconnected thereto are slidable in and out. To connect the liexible shaftwith the motor-shaft. the former is shoved in until the pin 19 engagesin the notch 20, and to disconnect the shaft it is pulled out asufficient distance to withdraw the pin from the notch. These actionscan be performed while the motor is running, and the tube 11 acts as thesupport for and guide 5 for the movement of the flexible shaft, so thatthe weight of said shaft is not borne by the motor shaft. The handpieeeand its shaft can be readily taken off by disconnecting thecoupling-sleeve 13. The movement 7 of the part 12 on the tube 11 ispreferably made tight enough to prevent unintentional engagement ordisengagement of the parts.

The extension of the motor-shaft beyond its casing and its support inthe arms 8 per- Inits the attachment of a fan, as indicated at 21. onthe shaft between the motor-casing and the arm. Furthermore, means todrive a rotary brush are provided, including a friction-wheel 22 on themotor-shaft and a fric- 8O tion-wheel 23 on the brush-shaft, engageabletherewith. The brush-shaft is indicated at 24 and the brush at 25. Thisshaft is carried in a bearing-box 26, which is slidable in a recess 27in the arm 8, projecting from the 5 head of the branch 8. A spring 28behind the bearing-box normally holds the wheels 22 and 23 out ofcontact. They may be thrown in contact to rotate the brush by slidingthe shaft 24 laterally, which may be conveniently 9 done by pressure onthe pin 29, which projects from the bearing-box 26 through a slot 30 inthe top of the arm 8 referred to. It will be seen that the brush isconveniently located and may be used even when the handpiece is idle.

WVhat We claim as new, and desire to secure by Letters Patent, is

g le-The combination with a driving-shaft and a support therefor, of atube projecting from the support, a flexible shaft having a covering,and a sleeve at the end of the covering, slidable on said tube, toconnect or disconnect the shafts.

2. The combination with a driving-shaft and a support therefor, of adriven flexible shaft engageable with said shaft and having a covering,a tube secured to the support and into which the end of the flexibleshaft extends, and a sleeve connecting the covering and the tube andslidable on the latter to connect or disconnect the shafts.

3. The combination with a driving-shaft, and a support having a bearingtherefor, of an inner tube and outer sleeve projecting from the supportaround said bearing, and a flexible shaft engagcable with thedriving-shaft and having a tubular covering, and a sleeve at the end ofsaid covering slidable between the tube and said outer sleeve, to engageor disengage the shafts.

4. The combination with a driving-shaft and a support therefor, of aflexible driven names to this specification in the presence of 4 twosubscribing witnesses.

\V M. BARKIN ALFORIV).

EDVI N P. ALFO RI).

\Vitnesses to \Villiain B. Alford:

JOHN L. BUuNs, \V. B. BURNS.

lVitnesscs toiEdwin P. Alford:

G. A. Lmmox, J. K. RosswELn.

